U.S. patent application number 16/265005 was filed with the patent office on 2019-08-01 for control device of hybrid vehicle.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Kenji GOTODA, Taku HARADA, Hiroki KUWAMOTO, Akira NAKATA, Yusuke TAKASU, Tomoya TAKEUCHI.
Application Number | 20190232949 16/265005 |
Document ID | / |
Family ID | 67391793 |
Filed Date | 2019-08-01 |
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United States Patent
Application |
20190232949 |
Kind Code |
A1 |
TAKASU; Yusuke ; et
al. |
August 1, 2019 |
CONTROL DEVICE OF HYBRID VEHICLE
Abstract
In a control device of a hybrid vehicle including an engine and
an electric motor serving as drive power sources and a damper
device disposed between the engine and the electric motor and
having rotational characteristics related to an input torque, the
control device comprises: a damper rotational characteristic
detecting portion configured to measure a rotational characteristic
value of the damper device by allowing the electric motor to input
a torque to the damper device while rotation of a crankshaft of the
engine is stopped; and an output torque correction control portion
configured to control an output torque of the engine or the
electric motor to suppress occurrence of vibration based on a
difference between the rotational characteristic value of the
damper device detected by the damper rotational characteristic
detecting portion and a preset initial setting value of the
rotational characteristic value of the damper device.
Inventors: |
TAKASU; Yusuke; (Toyota-shi,
JP) ; GOTODA; Kenji; (Nagakute-shi, JP) ;
KUWAMOTO; Hiroki; (Toyota-shi, JP) ; HARADA;
Taku; (Nisshin-shi, JP) ; NAKATA; Akira;
(Toyota-shi, JP) ; TAKEUCHI; Tomoya; (Okazaki-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
67391793 |
Appl. No.: |
16/265005 |
Filed: |
February 1, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60K 6/387 20130101;
B60W 2710/083 20130101; B60W 20/15 20160101; B60W 30/20 20130101;
B60W 2030/206 20130101; B60K 2006/268 20130101; B60W 2050/0075
20130101; B60W 10/08 20130101; B60W 50/0098 20130101; B60W 20/17
20160101; B60K 2006/381 20130101; B60Y 2200/92 20130101; B60W
2710/0666 20130101; B60W 10/06 20130101; B60K 6/22 20130101; B60K
6/445 20130101 |
International
Class: |
B60W 20/17 20060101
B60W020/17; B60W 10/06 20060101 B60W010/06; B60W 10/08 20060101
B60W010/08; B60K 6/22 20060101 B60K006/22 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 2018 |
JP |
2018-016800 |
Claims
1. A control device of a hybrid vehicle including an engine and an
electric motor serving as drive power sources and a damper device
disposed between the engine and the electric motor and having
rotational characteristics related to an input torque, the control
device comprising: a damper rotational characteristic detecting
portion configured to measure a rotational characteristic value of
the damper device by allowing the electric motor to input a torque
to the damper device while rotation of a crankshaft of the engine
is stopped; and an output torque correction control portion
configured to control an output torque of the engine or the
electric motor to suppress occurrence of vibration based on a
difference between the rotational characteristic value of the
damper device detected by the damper rotational characteristic
detecting portion and a preset initial setting value of the
rotational characteristic value of the damper device.
2. The control device of a hybrid vehicle according to claim 1,
wherein the hybrid vehicle includes an engine-side rotating element
fixing device stopping rotation of an engine-side rotating element
of the damper device, and wherein the damper rotational
characteristic detecting portion measures the rotational
characteristic value of the damper device by allowing the electric
motor to input a torque while the engine-side rotating element of
the damper device is fixed to the engine-side rotating element
fixing device.
3. The control device of a hybrid vehicle according to claim 1,
wherein the rotational characteristic value of the damper device is
any one of a rigidity value that is a rate of a twist angle to an
input torque of the damper device, a hysteresis value of the twist
angle for the input torque of the damper device, and a backlash
value indicative of a dead zone of the twist angle for the input
torque of the damper device.
4. The control device of a hybrid vehicle according to claim 2,
wherein the rotational characteristic value of the damper device is
any one of a rigidity value that is a rate of a twist angle to an
input torque of the damper device, a hysteresis value of the twist
angle for the input torque of the damper device, and a backlash
value indicative of a dead zone of the twist angle for the input
torque of the damper device.
5. The control device of a hybrid vehicle according to claim 3,
wherein when the rigidity value is larger than the preset initial
setting value, the output torque correction control portion
decreases the output torque of the engine with the rotation speed
of the engine kept constant, and wherein when the rigidity value is
smaller than the preset initial setting value, the output torque
correction control portion increases the output torque of the
engine with the rotation speed of the engine kept constant.
6. The control device of a hybrid vehicle according to claim 4,
wherein when the rigidity value is larger than the preset initial
setting value, the output torque correction control portion
decreases the output torque of the engine with the rotation speed
of the engine kept constant, and wherein when the rigidity value is
smaller than the preset initial setting value, the output torque
correction control portion increases the output torque of the
engine with the rotation speed of the engine kept constant.
7. The control device of a hybrid vehicle according to claim 3,
wherein when the hysteresis value is larger than the preset initial
setting value, the output torque correction control portion reduces
an initial explosion correction torque output from the electric
motor for starting the engine during electric-motor running, and
wherein when the hysteresis value is smaller than the preset
initial setting value, the output torque correction control portion
increases the initial explosion correction torque output from the
electric motor for starting the engine during the electric-motor
running.
8. The control device of a hybrid vehicle according to claim 4,
wherein when the hysteresis value is larger than the preset initial
setting value, the output torque correction control portion reduces
an initial explosion correction torque output from the electric
motor for starting the engine during electric-motor running, and
wherein when the hysteresis value is smaller than the preset
initial setting value, the output torque correction control portion
increases the initial explosion correction torque output from the
electric motor for starting the engine during the electric-motor
running.
9. The control device of a hybrid vehicle according to claim 3,
wherein when the backlash value is larger than the preset initial
setting value, the output torque correction control portion makes a
torque increase rate of a cranking torque output from the electric
motor larger, so that a backlash of the damper device is eliminated
smoothly and cranking is performed as quickly as possible at the
time of start of the engine, and wherein when the backlash value is
smaller than the preset initial setting value, the output torque
correction control portion makes the torque increase rate of the
cranking torque output from the electric motor smaller.
10. The control device of a hybrid vehicle according to claim 4,
wherein when the backlash value is larger than the preset initial
setting value, the output torque correction control portion makes a
torque increase rate of a cranking torque output from the electric
motor larger, so that a backlash of the damper device is eliminated
smoothly and cranking is performed as quickly as possible at the
time of start of the engine, and wherein when the backlash value is
smaller than the preset initial setting value, the output torque
correction control portion makes the torque increase rate of the
cranking torque output from the electric motor smaller.
Description
[0001] This application claims priority from Japanese Patent
Application No. 2018-016800 filed on Feb. 1, 2018, the disclosure
of which is herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a control device of a
hybrid vehicle and, more particularly, to a technique of
maintaining drivability by changing an engine torque or a motor
torque at the time of starting or driving an engine in accordance
with a change in characteristics of a damper device etc. to
suppress a tooth-hitting noise (gear rattle noise).
Description of the Related Art
[0003] There is known a hybrid vehicle including an engine and an
electric motor serving as drive power sources and a damper device
disposed between the engine and the electric motor and having
rotational characteristics related to an input torque. The damper
device is a device transmitting power through an elastic member so
as to absorb rotational vibration of the engine, for example, and
the rotational characteristics correspond to a rigidity
corresponding to a change in twist angle relative to a change in
the input torque, a hysteresis value that is a difference in the
input torque when the twist angle increases and decreases, a
backlash value that is a change amount of the twist angle at the
time of reversal between positive and negative in the input torque,
etc. In some cases, power performance, vibration, noise, etc. are
affected by the rotational characteristics of the damper device.
Therefore, efforts are made to improve power performance,
vibration, noise, etc. based on the rotational characteristics in
terms of both hardware and control. For example, in Patent Document
1, to prevent resonance from occurring in a vehicle due to rigidity
of a damper device when an electric motor is used as a drive power
source for running, a technique is proposed for changing a torque
of the electric motor so as to change the rigidity value of the
damper device based on a relationship between the input torque and
the rigidity value of the damper device.
CITATION LIST
[0004] Patent Document 1: Japanese Laid-Open Patent Publication No.
2016-107673
SUMMARY OF THE INVENTION
Technical Problem
[0005] Since a relationship between the input torque and the
rigidity value of the damper device varies depending on component
variation and temporal deterioration, an actual relationship may
deviate from a preset relationship. Therefore, if an output torque
of a drive power source is controlled in accordance with the preset
relationship based on a rotational characteristic value, the drive
power source is controlled while a deviation from the actual
relationship remains, so that a desired effect is not obtained for
suppression of occurrence of vibration such as a rattling noise and
a tooth-hitting noise, and/or suppression of vibrations such as an
engine start shock, etc., which may result in deterioration in
drivability.
[0006] The present invention was conceived in view of the
situations and it is therefore an object of the present invention
to suppress deterioration in drivability by properly providing
control based on a rotational characteristic value of a damper
device regardless of a change in the rotational characteristic
value.
Problem to Solution
[0007] To achieve the above object, a first aspect of the present
invention provides a control device of a hybrid vehicle including
(a) an engine and an electric motor serving as drive power sources
and a damper device disposed between the engine and the electric
motor and having rotational characteristics related to an input
torque, the control device comprising: (b) a damper rotational
characteristic detecting portion measuring a rotational
characteristic value of the damper device by allowing the electric
motor to input a torque to the damper device while rotation of a
crankshaft of the engine is stopped; and (c) an output torque
correction control portion controlling an output torque of the
drive power source to suppress occurrence of vibration based on a
difference between the rotational characteristic value of the
damper device detected by the damper rotational characteristic
detecting portion and a preset initial setting value of the
rotational characteristic value of the damper device.
[0008] A second aspect of the present invention provides the
control device of a hybrid vehicle recited in the first aspect of
the invention, wherein the hybrid vehicle includes an engine-side
rotating element fixing device stopping rotation of an engine-side
rotating element of the damper device, and wherein the damper
rotational characteristic detecting portion measures the rotational
characteristic value of the damper device by allowing the electric
motor to input a torque while the engine-side rotating element of
the damper device is fixed to the engine-side rotating element
fixing device.
[0009] A third aspect of the present invention provides the control
device of a hybrid vehicle recited in the first or second aspect of
the invention, wherein the rotational characteristic value of the
damper device is any one of a rigidity value that is a rate of a
twist angle to an input torque of the damper device, a hysteresis
value of the twist angle for the input torque, and a backlash value
indicative of a dead zone of the twist angle for the input
torque.
[0010] A fourth aspect of the present invention provides the
control device of a hybrid vehicle recited in the third aspect of
the invention, wherein when the rigidity value is larger than the
preset initial setting value, the output torque correction control
portion decreases the output torque of the engine with the rotation
speed of the engine kept constant, and wherein when the rigidity
value is smaller than the preset initial setting value, the output
torque correction control portion increases the output torque of
the engine with the rotation speed of the engine kept constant.
[0011] A fifth aspect of the present invention provides the control
device of a hybrid vehicle recited in the third aspect of the
invention, wherein when the hysteresis value is larger than the
preset initial setting value, the output torque correction control
portion reduces an initial explosion correction torque output from
the electric motor for starting the engine during electric-motor
running, and wherein when the hysteresis value is smaller than the
preset initial setting value, the output torque correction control
portion increases the initial explosion correction torque output
from the electric motor for starting the engine during the
electric-motor running.
[0012] A sixth aspect of the present invention provides the control
device of a hybrid vehicle recited in the third aspect of the
invention, wherein when the backlash value is larger than the
preset initial setting value, the output torque correction control
portion makes a torque increase rate of a cranking torque output
from the electric motor larger, so that a backlash of the damper
device is eliminated smoothly and cranking is performed as quickly
as possible at the time of start of the engine, and wherein when
the backlash value is smaller than the preset initial setting
value, the output torque correction control portion makes the
torque increase rate of the torque output from the electric motor
smaller.
Advantageous Effects of Invention
[0013] According to the control device of the hybrid vehicle
recited in the first aspect of the invention, the output torque
correction control portion controls the output torque of the drive
power source to suppress occurrence of vibration such as the
tooth-hitting noise and the engine start shock based on a
difference between the rotational characteristic value of the
damper device and the preset initial setting value of the
rotational characteristic value of the damper device. As a result,
regardless of a change in the rotational characteristic value of
the damper device, the occurrence of vibration such as the
tooth-hitting noise and the engine start shock is suppressed, and a
deterioration in vehicle drivability is suppressed.
[0014] According to the control device of the hybrid vehicle
recited in the second aspect of the invention, the hybrid vehicle
includes the engine-side rotating element fixing device stopping
rotation of the engine-side rotating element of the damper device,
and the damper rotational characteristic detecting portion measures
the rotational characteristic value of the damper device by
allowing the electric motor to input a torque while the input-side
rotating element of the damper device is fixed to the engine-side
rotating element fixing device. As a result, the rotational
characteristic value of the damper device is accurately
measured.
[0015] According to the control device of the hybrid vehicle
recited in the third aspect of the invention, the rotational
characteristic value of the damper device is any one of the
rigidity value that is a rate of the twist angle to the input
torque of the damper device, the hysteresis value of the twist
angle for the input torque, and the backlash value indicative of a
dead zone of the twist angle for the input torque, and therefore,
the control is properly provided based on the rotational
characteristic value regardless of a change in any of the rigidity
value, the hysteresis value, and the backlash value of the damper
device.
[0016] According to the control device of the hybrid vehicle
recited in the fourth aspect of the invention, when the rigidity
value is larger than the preset initial setting value, the output
torque correction control portion decreases the output torque of
the engine with the rotation speed of the engine kept constant, and
when the rigidity value is smaller than the preset initial setting
value, the output torque correction control portion increases the
output torque of the engine with the rotation speed of the engine
kept constant. As a result, even if the rigidity value of the
damper device changes, the occurrence of the rattling noise and
tooth-hitting noise is suppressed, and preferable fuel consumption
of the vehicle is achieved.
[0017] According to the control device of the hybrid vehicle
recited in the fifth aspect of the invention, when the hysteresis
value is larger than the preset initial setting value, the output
torque correction control portion reduces the initial explosion
correction torque output from the electric motor for starting the
engine during electric-motor running of the vehicle, and when the
hysteresis value is smaller than the preset initial setting value,
the output torque correction control portion increases the initial
explosion correction torque. As a result, even if the hysteresis
value of the damper device changes, an appropriate engine start
torque is obtained, so that the initial explosion of the engine is
properly performed without an engine start shock.
[0018] According to the control device of the hybrid vehicle
recited in the sixth aspect of the invention, when the backlash
value is larger than the preset initial setting value, the output
torque correction control portion makes the torque increase rate of
the torque output from the electric motor larger, so that the
backlash of the damper device is eliminated smoothly and cranking
of the engine is performed as quickly as possible at the time of
start of the engine, and when the backlash value is smaller than
the preset initial setting value, the output torque correction
control portion makes the torque increase rate of the torque output
from the electric motor smaller, so that the backlash of the damper
device is eliminated before starting the engine. As a result, even
if the backlash value of the damper device changes, the engine is
started after the backlash is eliminated smoothly and as quickly as
possible, so that the engine can smoothly be started.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 is a skeleton diagram for explaining a drive system
of a hybrid vehicle to which the present invention is applied,
showing main portions of the control system together.
[0020] FIG. 2 is a collinear chart of a differential mechanism of
the hybrid vehicle of FIG. 1.
[0021] FIG. 3 is a diagram of an example of a relationship between
an input torque and a twist angle of a damper device of FIG. 1.
[0022] FIG. 4 is a view illustrating a change characteristic of
rigidity of the damper device obtained from the relationship of
FIG. 3.
[0023] FIG. 5 is a view illustrating a change characteristic of a
hysteresis value of the damper device obtained from the
relationship of FIG. 3.
[0024] FIG. 6 is a view illustrating a change characteristic of a
backlash value of the damper device obtained from the relationship
of FIG. 3.
[0025] FIG. 7 is a diagram (map) showing a relationship between a
preset initial explosion correction torque and a rigidity value in
an electronic control device of FIG. 1.
[0026] FIG. 8 is a diagram showing a rattling noise suppression
line switched by the electronic control device of FIG. 1.
[0027] FIG. 9 shows a relationship between the initial explosion
correction torque, which is controlled by the electronic control
device of FIG. 1, and a tooth-hitting noise level.
[0028] FIG. 10 shows a preliminarily stored relationship between
the initial explosion correction torque, which is controlled by the
electronic control device of FIG. 1, and the hysteresis value.
[0029] FIG. 11 is a diagram showing an increase rate of a cranking
torque switched by the electronic control device of FIG. 1.
[0030] FIG. 12 is a flowchart for explaining main portions of an
example of the control operation of the electronic control device
of FIG. 1.
[0031] FIG. 13 is a flowchart for explaining main portions of an
example of the control operation of the electronic control device
of FIG. 1.
[0032] FIG. 14 is a flowchart for explaining the routine of step
S12 shown in FIG. 13.
[0033] FIG. 15 is a flowchart for explaining main portions of an
example of the control operation of the electronic control device
of FIG. 1.
[0034] FIG. 16 is a flowchart for explaining the routine of step
S14 shown in FIG. 15.
[0035] FIG. 17 is a flowchart for explaining main portions of an
example of the control operation of the electronic control device
of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The engine is an internal combustion engine generating power
from combustion of a fuel such as a gasoline engine and a diesel
engine. For the electric motor, a motor generator also usable as an
electric generator is suitably used. A rotational characteristic
value of a damper device is a rigidity value corresponding to a
change in twist angle relative to a change in input torque, a
hysteresis value that is a difference in the input torque when the
twist angle increases and decreases, or a backlash value that is a
change amount of the twist angle at the time of reversal between
positive and negative in the input torque, and the present
invention is applied when a predetermined torque control is
provided to improve vibration, noise, etc. based on any one of the
rotational characteristic values.
[0037] For an engine-side rotating element fixing device disposed
on an engine-side rotating element of the damper device and
stopping the rotation of the engine-side rotating element, a
friction brake of a hydraulic type etc., a meshing brake, or a
one-way clutch etc. is suitably used.
[0038] The damper rotational characteristic detecting portion
desirably continuously stores (learns) the rotational
characteristic value, for example, while a vehicle is stopped with
the engine stopped and a vehicle speed being zero or may detect the
value during motor running in which a second electric motor is used
as a drive power source for running with the engine stopped.
Regarding timing of the detection, the value may be learned at the
time of vehicle inspection or may periodically be learned based on
a predetermined running distance or a running time, and other
various forms are available. If temporal changes have a large
influence, it is desirable to periodically repeatedly detect the
value based on certain conditions.
[0039] If a drive power is generated due to the detection of the
rotational characteristic value, it is desirable to control torque
of the second electric motor to offset the drive power; however, in
the case of learning of the rotational characteristic value during
stop of the vehicle, for example, the learning may be performed on
condition that a depressing operation of a brake is performed, that
a shift lever is operated to a P (parking) position to put a
parking gear into an engaged state, or that a parking brake is in
operation. If the vehicle includes an automatic brake system which
automatically controls a brake force of a wheel brake, the wheel
brake may be actuated. If a drive power fluctuation including that
detected during running of the vehicle is slight, or in the case of
the learning before the shipment of the vehicle or during vehicle
inspecting, the offset control of the drive power may be omitted.
The offset control may not necessarily completely eliminate the
drive power fluctuation, and the drive power fluctuation is may be
reduced.
[0040] The present invention is applied to, for example, a hybrid
vehicle having a differential mechanism distributing an output of
an engine to an electric motor and a driving wheel side and may be
applied to various vehicles such as a one-motor hybrid vehicle
having an engine and an electric motor connected in series across a
rotating member such as a damper device and a hybrid vehicle
transmitting outputs of an engine and an electric motor combined by
a planetary gear device etc. toward driving wheels. A transmission
gear and a connecting/disconnecting device such as a clutch etc.
may be disposed as needed between the engine and the damper device
as well as between the damper device and the electric motor. If the
engine and the damper device are directly coupled via a coupling
shaft etc., the engine-side rotating element fixing device prevents
reverse rotation of the engine-side rotating element of the damper
device, i.e., the crankshaft of the engine, and the damper
rotational characteristic detecting portion applies a torque in the
reverse rotation direction to the damper device; however, if the
connecting/disconnecting device is disposed between the engine and
the damper device, the direction of the rotation of the damper
device to be prevented is not particularly limited. If rotation is
prevented in both directions by the engine-side rotating element
fixing device, the direction of the torque applied to the damper
device is not necessarily limited at the time of measurement of the
rotational characteristic value by the damper rotational
characteristic detecting portion. The rotational characteristics
can be obtained also by changing the torque in both positive and
negative directions.
EXAMPLE
[0041] An example of the present invention will now be described in
detail below with reference to the drawings.
[0042] FIG. 1 is a skeleton diagram for explaining a drive system
of a hybrid vehicle 10 to which the present invention is applied,
showing main portions of the control system together. The hybrid
vehicle 10 has, for example, a transversely-mounted drive system of
an FF (front-engine front-wheel drive) type etc. and includes in a
power transmission path between an engine 12 and a pair of left and
right driving wheels 14, a first drive portion 16, a second drive
portion 18, a final reduction gear 20, a pair of left and right
axles 22, etc.
[0043] The engine 12 is an internal combustion engine such as a
gasoline engine and a diesel engine and has a crankshaft 24 to
which a damper device 26 absorbing a torque fluctuation is coupled.
The damper device 26 includes an input-side rotating element 26a
coupled to the crankshaft 24 and an output-side rotating element
26b coupled via an input shaft 28 to a differential mechanism 30
with multiple types of springs 32 and a friction mechanism 34
interposed between the input-side rotating element 26a and the
output-side rotating element 26b, so that a rigidity value (spring
constant) K corresponding to a rate of a change in twist angle
.PHI. to a change in input torque Tin is changed stepwise while a
predetermined hysteresis value H is provided between when the twist
angle .PHI. increases and when the twist angle .PHI. decreases.
[0044] A torque limiter 35 is disposed on an outer circumferential
end portion of the damper device 26. The damper device 26 has a
backlash value G indicative of a dead zone of the twist angle .PHI.
for the input torque Tin as a rotational characteristic value.
[0045] The crankshaft 24 integrally coupled to the input-side
rotating element 26a is coupled to a housing 38 via a meshing brake
36 so that rotation is prevented. The meshing brake 36 has meshing
teeth 24a disposed on the crankshaft 24, meshing teeth 38a disposed
on the housing 38, and a meshing sleeve 36a having an inner
circumferential surface provided with meshing teeth which mesh
simultaneously with both the meshing teeth 24a, 38a, and the
meshing sleeve 36a is moved in an axial direction so that the
crankshaft 24 is switched between a state in which the crankshaft
24 is relatively non-rotatably engaged with the housing 38 and a
state in which the crankshaft 24 is released from the housing 38
and made freely rotatable.
[0046] For example, an electromagnetic switching valve etc.
disposed in a hydraulic control circuit 58 is switched in
accordance with a hydraulic control signal Sac supplied from an
electronic control device 90, so that the meshing sleeve 36a is
moved in the axial direction via a hydraulic cylinder etc. to
engage and release the meshing brake 36. Alternatively, the meshing
sleeve 36a can be moved in the axial direction by using another
drive device such as an electric feed screw mechanism. The meshing
brake 36 is provided with a synchronizing mechanism of a cone type
etc. as needed. The meshing brake 36 acts as to an input-side
rotating element fixing device, and instead of the meshing brake
36, a friction brake or a one-way clutch which prevents the engine
12 from rotating in only the reverse rotation direction can be
employed as the rotation lock mechanism. An engine
connecting/disconnecting clutch which enables/disenables power
transmission can be disposed between the engine 12 and the meshing
teeth 24a.
[0047] The first drive portion 16 is configured to include a first
electric motor MG1 and an output gear 40 in addition to the engine
12, the differential mechanism 30, and the meshing brake 36. The
differential mechanism 30 is a single pinion type planetary gear
device and includes a sun gear S, a ring gear R, and a carrier CA
as three rotating elements in a differentially rotatable manner;
the first electric motor MG1 is coupled to the sun gear S; the
input shaft 28 is coupled to the carrier CA; and the output gear 40
is coupled to the ring gear R.
[0048] Therefore, a torque transmitted from the engine 12 via the
damper device 26 to the carrier CA of the differential mechanism 30
is distributed by the differential mechanism 30 to the first
electric motor MG1 and the output gear 40, and when a rotation
speed (MG1 rotation speed) Nmg1 of the first electric motor MG1 is
controlled through regenerative control etc., a rotation speed
(engine rotation speed) Ne of the engine 12 is continuously
variably changed and output from the output gear 40. Therefore, the
differential mechanism 30 and the first electric motor MG1 function
as an electric continuously variable transmission. The first
electric motor MG1 alternatively functions as an electric motor or
an electric generator and is connected through an inverter 60 to an
electric storage device 62.
[0049] On the other hand, when the first electric motor MG1 is
rotationally driven in a negative rotation direction opposite to a
running direction of the engine 12 while the rotation of the
crankshaft 24 is prevented by the meshing brake 36, i.e., while a
rotation of the carrier CA is prevented via the damper device 26, a
torque is applied to the output gear 40 in the positive rotation
direction (vehicle forward direction) same as the running direction
of the engine 12 due to a reaction force generated by the meshing
brake 36, and the output gear 40 is rotationally driven in the
positive rotation direction. When the first electric motor MG1 is
rotationally driven in the positive rotation direction same as the
running direction of the engine 12, a torque is applied to the
output gear 40 in the reverse rotation direction (vehicle reverse
direction) opposite to the running direction of the engine 12 due
to a reaction force generated by the meshing brake 36, and the
output gear 40 is rotationally driven in the reverse rotation
direction. In such a case, a torque Tm1 of the first electric motor
MG1 is amplified depending on a gear ratio .rho. of the
differential mechanism 30 and applied to the damper device 26
coupled to the carrier CA. The first electric motor MG1 is an
electric motor which applies a torque to the damper device 26 via
the differential mechanism 30.
[0050] FIG. 2 is a collinear chart in which the three rotating
elements of the differential mechanism 30, i.e., the sun gear S,
the ring gear R, and the carrier CA, can be connected by a straight
line in terms of rotation speed; the upward direction of FIG. 2 is
the running direction of the engine 12, i.e., the positive rotation
direction; and intervals among the vertical axes are determined
depending on the gear ratio .rho. (=the number of teeth of the sun
gear S/the number of teeth of the ring gear R) of the differential
mechanism 30. For example, describing a case that the output gear
40 is rotationally driven in the vehicle forward direction by the
first electric motor MG1, a torque of rotation in the negative
rotation direction (the downward direction of FIG. 2) opposite to
the running direction of the engine 12 is applied to the sun gear S
as indicated by an arrow YA through a power running control of the
first electric motor MG1 while the rotation of the carrier CA is
prevented by the meshing brake 36, and when the sun gear S is
rotationally driven in the negative rotation direction, a torque of
rotation in the positive rotation direction (the upward direction
of FIG. 2) same as the running direction of the engine 12 is
applied as indicated by an arrow YB to the ring gear R to which the
output gear 40 is coupled, so that a drive power is obtained in the
forward direction.
[0051] Returning to FIG. 1, the output gear 40 is meshed with a
large diameter gear 44 disposed on an intermediate shaft 42
parallel to the input shaft 28. A dog clutch 43 is disposed between
the large diameter gear 44 and the intermediate shaft 42 so that a
power transmission is selectively switched between to be enabled
and disenabled. This dog clutch 43 is configured in the same way as
the meshing brake 36, for example and has an engaged state and a
disengaged state switched therebetween via a hydraulic cylinder
etc. when another electromagnetic switching valve etc. disposed in
the hydraulic control circuit 58 is switched in accordance with the
hydraulic control signal Sac supplied from the electronic control
device 90, so that the power transmission is enabled and disenabled
between the large diameter gear 44 and the intermediate shaft
42.
[0052] A small diameter gear 46 smaller in diameter than the large
diameter gear 44 is disposed on the intermediate shaft (counter
shaft) 42, and the small diameter gear 46 is meshed with a
differential ring gear 48 of the final reduction gear 20.
Therefore, the rotation of the output gear 40 is reduced in speed
depending on a ratio of the numbers of teeth between the output
gear 40 and the large diameter gear 44 and a ratio of the numbers
of teeth between the small diameter gear 46 and the differential
ring gear 48 and transmitted to the final reduction gear 20 and is
further transmitted from the pair of the axles 22 to the driving
wheels 14 through a differential gear mechanism of the final
reduction gear 20. A parking gear 45 is relatively non-rotatably
disposed on the intermediate shaft 42, and when a parking range is
selected by operation of a shift lever to a P position for parking
etc., a parking lock pawl not shown is pressed against and meshed
with the parking gear 45 in accordance with an urging force of a
spring etc. so as to prevent rotation of members on the driving
wheel 14 side from the intermediate shaft 42.
[0053] The second drive portion 18 is configured to include a
second electric motor MG2 and a motor output gear 52 disposed on a
motor shaft 50 of the second electric motor MG2, and the motor
output gear 52 is meshed with the large diameter gear 44.
Therefore, a rotation speed (MG2 rotation speed Nmg2) of the second
electric motor MG2 is reduced depending on a ratio of the number of
teeth between the motor output gear 52 and the large diameter gear
44 and a ratio of the number of teeth between the small diameter
gear 46 and the differential ring gear 48 and transmitted to the
final reduction gear 20 to rotationally drive the driving wheels 14
via the pair of the axles 22. The second electric motor MG2
alternatively functions as an electric motor and an electric
generator and is connected through the inverter 60 to the electric
storage device 62. The second electric motor MG2 corresponds to a
second electric motor usable as a drive power source.
[0054] The hybrid vehicle 10 also includes an automatic brake
system 66. The automatic brake system 66 electrically controls a
brake force i.e. a brake hydraulic pressure, of each of wheel
brakes 67 disposed on the pair of driving wheels 14 and a pair of
driven wheels (non-driving wheels) not shown in accordance with a
brake control signal Sb supplied from the electronic control device
90. The wheel brake 67 is also supplied with a brake hydraulic
pressure via a brake master cylinder when a brake pedal not shown
is depressed, so that a brake force is mechanically generated
depending on the brake hydraulic pressure, i.e., a brake operating
force.
[0055] The hybrid vehicle 10 having the drive system configured as
described above includes the electronic control device 90 as a
controller providing various controls such as an output control of
the engine 12, a torque control of the first and second electric
motors MG1, MG2, an engagement/release control of the meshing brake
36 and the dog clutch 43, a control of automatic braking by the
automatic brake system 66. The electronic control device 90
includes a so-called microcomputer having a CPU, a RAM, a ROM, an
input/output interface, etc. and executes a signal process
according to a program stored in advance in the ROM, while
utilizing a temporary storage function of the RAM to provide the
various controls.
[0056] The electronic control device 90 is supplied with signals
indicative of various pieces of information required for control
such as the engine rotation speed Ne (rpm), a vehicle speed V
(km/h), the MG1 rotation speed Nmg1 (rpm), the MG2 rotation speed
Nmg2 (rpm), an accelerator operation amount Acc (%), a shift lever
operation position Psh, and an electric storage remaining amount
SOC (%) of the electric storage device 62, from an engine rotation
speed sensor 70, a vehicle speed sensor 72, an MG1 rotation speed
sensor 74, an MG2 rotation speed sensor 76, an accelerator
operation amount sensor 78, a shift position sensor 80, and an SOC
sensor 64, respectively, for example. Examples of the shift lever
operation position Psh include a D position for forward running, an
R position for reverse running, the P position for parking, and an
N position for neutral, and when the parking range is selected by
operation to the P position, the parking lock pawl is meshed with
the parking gear 45 disposed on the intermediate shaft 42 so that
rotation of the parking gear 45 is mechanically prevented.
[0057] The electronic control device 90 outputs, for example, an
engine control signal Se for controlling an engine output through
an electronic throttle valve, a fuel injection device, an ignition
device, etc. of the engine 12, a motor control signal Sm for
controlling torques (power running torque and regenerative torque)
of the first and second electric motors MG1 and MG2, the hydraulic
control signal Sac switching the meshing brake 36 and the dog
clutch 43 between engaged and disengaged states via the
electromagnetic switching valve etc. of the hydraulic control
circuit 58, and the brake control signal Sb controlling the brake
force of the wheel brake 67 via the automatic brake system 66.
[0058] The electronic control device 90 corresponds to a vehicle
control device of the present invention and functionally includes a
damper rotational characteristic detecting portion 92, a damper
rotational characteristic storage portion 94, and an output torque
correction control portion 96 to provide a predetermined control
for improving vibration, noise, etc. based on a rigidity, a
hysteresis value, or a backlash value that is a characteristic of
the damper device 26.
[0059] The damper device 26 has a relationship between the input
torque Tin to the damper device 26 and the twist angle .PHI., for
example, as shown in FIG. 3, due to the action of the springs 32
and the friction mechanism 34 etc. Although FIG. 3 shows a
symmetric change with respect to an origin O, the damper device 26
causing an asymmetric change is also employable. From the
relationship between the input torque Tin and the twist angle
.PHI., the characteristics related to the rigidity value K, the
hysteresis value H, and the backlash value G respectively shown in
FIGS. 4 to 6 can be identified.
[0060] The rigidity value K (Nm/rad) is a change (gradient) of the
twist angle .PHI. relative to a change of the input torque Tin and
FIG. 4 shows three kinds K1, K2, K3 of a rigidity value such that
the rigidity value changes at two change points A1, A2 different in
the input torque Tin. Therefore, the rigidity value is K1 in a
region of the input torque Tin equal to or less than A1, the
rigidity value is K2 in a region from A1 to A2, and the rigidity
value is K3 in a region greater than A2. For example, at least one
of the values K1, K2, K3 or an average value thereof etc. are used
as the rigidity value K.
[0061] The hysteresis value H (Nm) of FIG. 5 is a deviation of the
input torque Tin when the twist angle .PHI. increases and decreases
and is obtained by offsetting an amount corresponding to the
rigidity and extracting only the deviation.
[0062] The backlash value G (rad) of FIG. 6 is a change amount of
the twist angle .PHI. at the time of reversal between positive and
negative in the input torque Tin and is an amount of a play between
the input-side rotating element 26a and the output-side rotating
element 26b of the damper device 26.
[0063] The damper rotational characteristic detecting portion 92
detects the twist angle .PHI. when the torque Tin is input from the
first electric motor MG1 to the output-side rotating element 26b of
the damper device 26 while the input-side rotating element
(engine-side rotating element) 26a of the damper device 26 is fixed
to the meshing brake 36 functioning as an engine-side rotating
element fixing device of the present invention, thereby repeatedly
calculates (measures) at least one of actual rotational
characteristic values of the damper device 26, i.e., the actual
rigidity value K, the actual hysteresis value H, and the actual
backlash value G at predetermined intervals or at the time of
completion of running of a certain running distance etc., and
sequentially stores the value in the damper rotational
characteristic storage portion 94.
[0064] The damper rotational characteristic storage portion 94 has
preset initial setting values Ki, Hi, Gi stored therein for the
rotational characteristic values, i.e., at least one of the
rigidity value K, the hysteresis value H, and the backlash value G
These initial setting values Ki, Hi, Gi are values initially preset
at the time of manufacturing, factory shipment, or sale by a
dealer, as values on the most disadvantageous side in terms of
occurrence of vibration such as rattling noise and tooth-hitting
noise in consideration of design tolerances, or variations in the
values detected by the damper rotational characteristic detecting
portion 92, when preset initial conditions are satisfied.
[0065] Based on a difference between the rotational characteristic
value of the damper device 26 and the preset initial setting value
of the rotational characteristic value of the damper device 26, the
output torque correction control portion 96 corrects and controls
the output torque Te of the engine 12 or the output torque Tm1 of
the first electric motor MG1 to suppress occurrence of vibration
such as the tooth-hitting noise and the engine start shock.
[0066] For example, to suppress noise or vibration referred to as
tooth-hitting noise at the engine start, the output torque
correction control portion 96 determines an initial explosion
correction torque Tc based on the actual rigidity value K detected
by the damper rotational characteristic detecting portion 92 from a
preset relationship (map) shown in FIG. 7, for example, and adds
this initial explosion correction torque Tc to a base value of a
cranking torque Tk from the first electric motor MG1 calculated in
accordance with a vehicle mode (an acceleration request mode, a
warm-up mode, a charge mode, etc.) at the time of a start request
of the engine 12 during electric-motor running, for example. The
initial explosion correction torque Tc is determined in accordance
with a difference of the actual rigidity value K from the initial
value Ki shown in FIG. 7, and as the actual rigidity value K
becomes lower than the initial value Ki, the initial explosion
correction torque Tc is determined as a smaller value.
[0067] For example, to suppress noise or vibration such as rattling
noise during running, when the actual rigidity value K detected by
the damper rotational characteristic detecting portion 92 is larger
than the preset initial setting value Ki of the rigidity value, the
output torque correction control portion 96 decreases the output
torque Te of the engine 12 with the rotation speed Ne of the engine
12 in operation kept constant, and when the actual rigidity value K
is smaller than the preset initial setting value Ki, the output
torque correction control portion 96 increases the output torque Te
of the engine 12 with the rotation speed Ne of the engine 12 in
operation kept constant.
[0068] Specifically, as shown in FIG. 8, when the actual rigidity
value K is equivalent to the preset initial setting value Ki of the
rigidity value, an ordinary rattling noise suppression line LB is
used; however, when the actual rigidity value K is larger than the
preset initial setting value Ki of the rigidity value, the ordinary
rattling noise suppression line LB is switched to a low-torque-side
rattling noise suppression line LA set on the lower torque side,
and an operating point of the engine 12 is set on the
low-torque-side rattling noise suppression line LA without changing
the rotation speed Ne of the engine 12 in operation. When the
actual rigidity value K is smaller than the preset initial setting
value Ki of the rigidity value, the ordinary rattling noise
suppression line LB is switched to a high-torque-side rattling
noise suppression line LC set on the higher torque side, and the
operating point of the engine 12 is set on the high-torque-side
rattling noise suppression line LC without changing the rotation
speed Ne of the engine 12 in operation.
[0069] Therefore, for example, when the operating point of the
engine 12 is a point Pb i.e., the actual rigidity value K is
equivalent to the preset initial setting value Ki of the rigidity
value, and the actual rigidity value K is larger than the preset
initial setting value Ki of the rigidity value, torque control is
executed such that the operating point of the engine 12 is shifted
from the point Pb to a point Pa without changing the rotation speed
Ne of the engine 12, and if the actual rigidity value K is smaller
than the preset initial setting value Ki of the rigidity value,
torque control is executed such that the operating point of the
engine 12 is shifted from the point Pb to a point Pc without
changing the rotation speed Ne of the engine 12.
[0070] For example, to suppress noise or vibration such as rattling
noise during running, when the actual hysteresis value H detected
by the damper rotational characteristic detecting portion 92 is
smaller than the preset initial setting value Hi, the output torque
correction control portion 96 decreases the output torque Te of the
engine 12 with the rotation speed Ne of the engine 12 in operation
kept constant, and when the actual hysteresis value H is larger
than the preset initial setting value Hi, the output torque
correction control portion 96 increases the output torque Te of the
engine 12 with the rotation speed Ne of the engine 12 in operation
kept constant.
[0071] Specifically, as shown in FIG. 8, when the actual hysteresis
value H is equivalent to the preset initial setting value Hi of the
hysteresis value H, an ordinary rattling noise suppression line LB
is used. However, when the actual hysteresis value H is smaller
than the preset initial setting value Hi of the hysteresis value H,
the ordinary rattling noise suppression line LB is switched to a
low-torque-side rattling noise suppression line LA set on the lower
torque side, and the operating point of the engine 12 is set on the
low-torque-side rattling noise suppression line LA without changing
the rotation speed Ne of the engine 12 in operation. When the
actual hysteresis value H is larger than the preset initial setting
value Hi of the hysteresis value H, the ordinary rattling noise
suppression line LB is switched to a high-torque-side rattling
noise suppression line LC set on the higher torque side, and the
operating point of the engine 12 is set on the high-torque-side
rattling noise suppression line LC without changing the rotation
speed Ne of the engine 12 in operation.
[0072] Therefore, as shown in FIG. 8, for example, when the
operating point of the engine 12 is the point Pb when the actual
hysteresis value H is equivalent to the preset initial setting
value Hi of the hysteresis value H, if the actual hysteresis value
H is smaller than the preset initial setting value Hi of the
hysteresis value H, torque control is executed such that the
operating point of the engine 12 is shifted from the point Pb to
the point Pa without changing the rotation speed Ne of the engine
12, and if the actual hysteresis value H is larger than the preset
initial setting value Hi of the hysteresis value H, a torque is
controlled such that the operating point of the engine 12 is
shifted from the point Pb to the point Pc without changing the
rotation speed Ne of the engine 12.
[0073] In FIG. 8, a normal operation line Lu indicated by a broken
line is a target operation line experimentally obtained in advance
to operate the engine 12 such that both a driving performance and a
fuel consumption performance are satisfied. On the other hand, the
rattling noise suppression line LA, LB, LC is an operation line
experimentally obtained in advance to set the engine rotation speed
Ne higher than the normal operation line Lu so as to avoid an area
in which a tooth-hitting noise, i.e., a rattling noise, is likely
to occur during operation of the engine 12. The ordinary rattling
noise suppression line LB is set at the time of a maximum value
among the tolerances (variations) of the rigidity of the springs 32
of the damper device 26. When the engine rotation speed Ne enters a
low rotation region and the engine output torque Te enters the low
output torque region, the normal operation line Lu for operating
the engine 12 is switched to any one of the rattling noise
suppression lines LA, LB, LC. In this example, the ordinary
rattling noise suppression line LB is set as an ordinary rattling
noise suppression line along with the rattling noise suppression
line LA set on the lower torque side than the ordinary rattling
noise suppression line LB and the rattling noise suppression line
LC set on the higher torque side than the ordinary rattling noise
suppression line LB.
[0074] FIG. 9 shows a relationship between the initial explosion
correction torque Tc (Nm) required for suppressing the
tooth-hitting noise generated at the time of cranking and a
tooth-hitting noise level Lv (dB) generated at the time of
cranking, which shows that when the initial explosion correction
torque Tc becomes larger, the tooth-hitting noise level Lv (dB)
becomes smaller. FIG. 10 shows a preliminarily stored relationship
between the initial explosion correction torque Tc and the
hysteresis value H of the damper device 26 that as the hysteresis
value H of the damper device 26 becomes larger, the initial
explosion correction torque Tc becomes smaller.
[0075] For example, to suppress the tooth-hitting noise or the
start shock generated at the time of cranking of the engine 12 by
the first electric motor MG1, when the actual hysteresis value H
detected by the damper rotational characteristic detecting portion
92 is larger than the preset initial setting value Hi, the output
torque correction control portion 96 reduces the initial explosion
correction torque Tc required for suppressing the tooth-hitting
noise generated at the time of cranking for starting the engine 12
during the electric-motor running using the second electric motor
MG2, and when the hysteresis value H is smaller than the preset
initial setting value Hi, the output torque correction control
portion 96 increases the initial explosion correction torque
Tc.
[0076] Specifically, when the actual hysteresis value H is
equivalent to the initial setting value Hi, the output torque
correction control portion 96 does not change (correct) the
cranking torque Tk from the first electric motor MG1 for cranking
the engine 12; however, when the actual hysteresis value H is
larger than the preset initial setting value Hi of the hysteresis
value H, for example, when the actual hysteresis value H increases
to a value Hc from the relationship of FIG. 10, the output torque
correction control portion 96 reduces the initial explosion
correction torque Tc to a value Tcc. Conversely, when the actual
hysteresis value H is smaller than the preset initial setting value
Hi of the hysteresis value H, for example, when the actual
hysteresis value H decreases to a value Ha from the relationship of
FIG. 10, the output torque correction control portion 96 increases
the initial explosion correction torque Tc to a value Tca. The
initial explosion correction torque Tc determined in this way is
added to the base value of the cranking torque Tk of the first
electric motor MG1 calculated in accordance with the vehicle mode
(the acceleration request mode, the warm-up mode, the charge mode,
etc.) at the time of the start request of the engine 12 during the
electric-motor running, for example.
[0077] For example, to suppress the tooth-hitting noise or the
start shock generated at the time of cranking of the engine 12 by
the first electric motor MG1 to perform cranking smoothly and as
quickly as possible for the backlash value G of the damper device
26 at the start of the engine 12, the output torque correction
control portion 96 makes a torque increase rate of the cranking
torque Tk output from the first electric motor MG1 larger when the
actual backlash value G of the damper device 26 detected by the
damper rotational characteristic detecting portion 92 is larger
than the preset initial setting value Gi, and the output torque
correction control portion 96 makes the torque increase rate of the
cranking torque Tk smaller when the backlash value G is smaller
than the preset initial setting value Gi, so that.
[0078] Specifically, when the actual backlash value G of the damper
device 26 detected by the damper rotational characteristic
detecting portion 92 is equivalent to the preset initial setting
value Gi, the output torque correction control portion 96 sets the
cranking torque Tk to a torque increase rate indicated by a broken
line TkB of FIG. 11; however, when the actual backlash value G is
larger than the preset initial setting value Gi, the output torque
correction control portion 96 makes the torque increase rate of the
cranking torque Tk relatively larger than the line TkB as indicated
by a dashed dotted line TkC of FIG. 11, and when the backlash value
G is smaller than the preset initial setting value Gi, the output
torque correction control portion 96 makes the torque increase rate
of the cranking torque Tk relatively smaller than the line TkB as
indicated by a solid line TkA of FIG. 11.
[0079] FIG. 12 is a flowchart for explaining main portions of an
example of the control operation of the electronic control device
90. In FIG. 12, when a rotational characteristic value of the
damper device 26 is detected at step S1 (hereinafter referred to as
S1) corresponding to the damper rotational characteristic detecting
portion 92, S2 to S5 corresponding to the output torque correction
control portion 96 are executed. At S2, it is determined whether
the rotational characteristic value detected at S1 is on the
disadvantageous side relative to the initial setting value of the
rotational characteristic value in terms of occurrence of
vibrations of the tooth-hitting noise etc. For example, when the
rotational characteristic value is the actual hysteresis value H of
the damper device 26, it is determined whether the value H is on
the side where the vibrations of the tooth-hitting noise etc.
become larger, relative to the initial setting value Hi.
[0080] In the case that the determination of S2 is negative, at S3,
for example, if a more advantageous map exists as compared to when
the correction torque corresponding to the initial setting value is
used, the correction torque is changed based on the map. For
example, if a value of initial explosion correction torque Tc can
be obtained based on a map that is more advantageous as compared to
when the initial explosion correction torque Tc corresponding to
the initial setting value Hi is used, the initial explosion
correction torque Tc is corrected (changed) to the value.
[0081] However, if the determination of S2 is affirmative, at S4,
the correction torque is changed based on the actual rotational
characteristic value and the map stored in advance. For example,
the initial explosion correction torque Tc is determined based on
the actual hysteresis value H from the preliminarily stored
relationship. For example, the initial explosion correction torque
Tc is determined based on the actual hysteresis value H from the
preliminarily stored relationship shown in FIG. 7. In FIG. 7, when
the actual hysteresis value H is smaller than the initial setting
value Hi and is on the disadvantageous side, a smaller value is
determined for the initial explosion correction torque Tc as
compared to when the initial explosion correction torque Tc
corresponding to the initial setting value Hi is used.
[0082] Regarding selection of the rattling noise suppression line,
as shown in FIG. 8, when the actual hysteresis value H is
equivalent to the preset initial setting value Hi, the ordinary
rattling noise suppression line LB is used.
[0083] However, when the actual hysteresis value H is smaller than
the preset initial setting value Hi, the ordinary rattling noise
suppression line LB is switched to the low-torque-side rattling
noise suppression line LA set on the lower torque side, and the
operating point of the engine 12 is set on the low-torque-side
rattling noise suppression line LA without changing the rotation
speed Ne of the engine 12 in operation.
[0084] When the actual hysteresis value H is larger than the preset
initial setting value Hi, the ordinary rattling noise suppression
line LB is switched to the high-torque-side rattling noise
suppression line LC set on the higher torque side, and the
operating point of the engine 12 is set on the high-torque-side
rattling noise suppression line LC without changing the rotation
speed Ne of the engine 12 in operation.
[0085] At S5, it is determined whether another rotational
characteristic is detected at S1. If the determination of S5 is
affirmative, S2 and subsequent steps are executed, and if the
determination is negative, this routine is terminated.
[0086] To optimize the output torque Te of the engine 12 in
accordance with the actual rigidity value K of the damper device 26
and suppress the occurrence of the rattling noise during operation
of the engine 12, the electronic control device 90 can provide
control shown in FIGS. 13 and 14.
[0087] At S11 of FIG. 13, it is determined whether the vehicle
running status is in the rattling noise generation region when an
accelerator pedal is returned during running of the vehicle 10. The
determination is made for example, based on whether the output
torque Tm2 of the second electric motor MG2 comes close to zero
(Nm) while the vehicle 10 is running. If the determination of S11
is negative, this routine is terminated, and if the determination
of S11 is affirmative, at S12, an appropriate rattling noise
suppression line corresponding to the vehicle speed V is
selected.
[0088] FIG. 14 is a flowchart for explaining the routine of S12. In
FIG. 14, when the actual rigidity value K of the damper device 26
is detected as one of the rotational characteristic values at S121
corresponding to the damper rotational characteristic detecting
portion 92, S122 to S126 corresponding to the output torque
correction control portion 96 are executed.
[0089] At S122, it is determined whether the actual rigidity value
K detected at S121 is equivalent to the preset initial setting
value Ki. If the determination of S122 is affirmative, the output
torque control of the engine 12 is not changed at S123.
Specifically, this is the case that the actual rigidity value K is
equivalent to the preset initial setting value Ki of the rigidity
value K, and therefore, for example, the operating point of the
engine 12 is maintained at the point Pb on the rattling noise
suppression line LB of FIG. 8. However, if the determination of
S122 is negative, it is determined at S124 whether the actual
rigidity value K is larger than the preset initial setting value
Ki.
[0090] If the determination of S124 is affirmative, this is the
case that the actual rigidity value K is larger than the preset
initial setting value Ki of the rigidity value K, and therefore, at
S125, the torque Te of the engine 12 is controlled such that the
operating point of the engine 12 is shifted from the point Pb to
the point Pa on the rattling noise suppression line LA without
changing the rotation speed Ne of the engine 12 as shown in FIG.
8.
[0091] However, if the determination of S124 is negative, this is
the case that the actual rigidity value K is smaller than the
preset initial setting value Ki of the rigidity value K, and
therefore, at S126, the torque Te of the engine 12 is controlled
such that the operating point of the engine 12 is shifted from the
point Pb to the point Pc on the rattling noise suppression line LC
without changing the rotation speed Ne of the engine 12.
[0092] To optimize the cranking torque Tk from the first electric
motor MG1 for cranking the engine 12 in accordance with the actual
hysteresis value H and suppress the tooth-hitting noise and the
start shock, the electronic control device 90 can provide control
shown in FIGS. 15 and 16.
[0093] At S13 of FIG. 15, it is determined whether the maximum
value of the cranking torque Tk is reduced by the initial explosion
correction torque Tc. If the determination of S13 is negative, this
routine is terminated, and if the determination of S13 is
affirmative, the process shown in FIG. 16 is executed at S14 to
calculate the initial explosion correction torque Tc based on the
actual hysteresis value H.
[0094] In FIG. 16, when the actual hysteresis value H of the damper
device 26 is detected as one of the rotational characteristic
values at S141 corresponding to the damper rotational
characteristic detecting portion 92, S142 to S146 corresponding to
the output torque correction control portion 96 are executed.
[0095] At S142, it is determined whether the actual hysteresis
value H is equivalent to the preset initial setting value Hi of the
hysteresis value H. If the determination of S142 is affirmative, at
S143, the initial explosion correction torque Tc is maintained at a
value Tcb of FIG. 10 and no change is made to the cranking torque
Tk from the first electric motor MG1 to which this value is added
as described later. However, if the determination of S142 is
negative, it is determined at S144 whether the actual hysteresis
value H is larger than the preset initial setting value Hi.
[0096] If the determination of S144 is affirmative, this is the
case that the actual hysteresis value H is larger than the preset
initial setting value Hi, and therefore, at S145, the initial
explosion correction torque Tc is reduced to the value Tcc shown in
FIG. 10, for example.
[0097] Conversely, if the determination of S144 is negative, this
is the case that the actual hysteresis value H is smaller than the
preset initial setting value Hi, and therefore, the torque Tc is
increased to the value Tca of FIG. 10.
[0098] Returning to FIG. 15, at S15, a motor torque base value of
the second electric motor MG2 outputting a drive torque of the
vehicle 10 is calculated from a preset relationship based on an
engine operation mode such as the acceleration request mode, the
charge mode, and the warm-up mode.
[0099] Subsequently, at S16, a temporary complete explosion
addition motor torque at complete explosion is calculated as the
output torque Tm2 of the second electric motor MG2 acquired by
adding an expected torque at the time of complete explosion of the
engine 12 to the motor torque base value of the second electric
motor MG2 calculated at S15.
[0100] Subsequently, at S17, a pushing torque for eliminating the
backlash added to the output torque of the second electric motor
MG2 performing electric-motor running is calculated for eliminating
an influence of a reaction force generated at the time of engine
start by the first electric motor MG1 and is added to the temporary
addition motor torque at complete explosion calculated at S16.
[0101] At S18, the initial explosion correction torque Tc
calculated at S14 is added to the torque value calculated at S17.
With the cranking torque Tk after the addition, the engine 12 is
cranked by the first electric motor MG1.
[0102] To optimize the cranking torque Tk from the first electric
motor MG1 at the time of cranking of the engine 12 in accordance
with the actual backlash value G and suppress the tooth-hitting
noise and the start shock, the electronic control device 90 can
provide control shown in FIG. 17. When the actual backlash value G
of the damper device 26 is detected as one of the rotational
characteristic values at step S19 in FIG. 17 corresponding to the
damper rotational characteristic detecting portion 92, S20 to S24
corresponding to the output torque correction control portion 96
are executed.
[0103] At S20, it is determined whether the actual backlash value G
detected at S19 is equivalent to the preset initial setting value
Gi.
[0104] If the determination of S20 is affirmative, the cranking
torque Tk output by the first electric motor MG1 is not changed at
S21. Specifically, this is the case that the actual backlash value
G is equivalent to the preset initial setting value Gi of the
backlash value and therefore, the cranking torque characteristic
TkB is selected for the cranking torque Tk of FIG. 11, for
example.
[0105] However, if the determination of S20 is negative, it is
determined at S22 whether the actual backlash value G is larger
than the preset initial setting value Gi.
[0106] If the determination of S22 is affirmative, this is the case
that the actual backlash value G is larger than the preset initial
setting value Gi of the backlash value G, and therefore, at S23,
the cranking torque characteristic TkC rising faster (having a
larger torque rate) than the cranking torque characteristic TkB is
selected as shown in FIG. 11. As a result, backlash is quickly
eliminated.
[0107] However, if the determination of S22 is negative, this is
the case that the actual backlash value G is smaller than the
preset initial setting value Gi of the backlash value G, and
therefore, at S24, the cranking torque characteristic TkA rising
later (having a smaller torque rate) than the cranking torque
characteristic TkB is selected.
[0108] As described above, according to the electronic control
device 90 of the hybrid vehicle 10 of this example, the output
torque correction control portion 96 controls the output torque of
the drive power source such as the engine 12, the first electric
motor MG1, and the second electric motor MG2 to suppress occurrence
of vibration such as the tooth-hitting noise and the engine start
shock based on a difference between the rotational characteristic
value of the damper device 26 detected by the damper rotational
characteristic detecting portion 92 and the preset initial setting
value of the rotational characteristic value of the damper device
26. As a result, regardless of a change in the rotational
characteristic value of the damper device 26, the occurrence of
vibration such as the tooth-hitting noise and the engine start
shock is suppressed, and a deterioration in vehicle drivability is
suppressed.
[0109] According to the electronic control device 90 of the hybrid
vehicle 10 of this example, the hybrid vehicle 10 includes the
meshing brake (engine-side rotating element fixing device) 36
stopping rotation of the input-side rotating element (engine-side
rotating element) 26a of the damper device 26, and the damper
rotational characteristic detecting portion 92 measures the
rotational characteristic value of the damper device 26 by allowing
the first electric motor MG1 to input a torque while the input-side
rotating element 26a of the damper device 26 is fixed to the
meshing brake 36. As a result, the rotational characteristic value
of the damper device 26 is accurately measured.
[0110] According to the electronic control device 90 of the hybrid
vehicle 10 of this example, the rotational characteristic value of
the damper device 26 is any one of the rigidity value K that is a
rate of the twist angle .PHI. to the input torque Tin of the damper
device 26, the hysteresis value H of the twist angle .PHI. for the
input torque Tin, and the backlash value G indicative of a dead
zone of the twist angle .PHI. for the input torque Tin, and
therefore, the torque control is properly provided based on the
rotational characteristic value regardless of a change in any of
the rigidity value K, the hysteresis value H, and the backlash
value G of the damper device 26.
[0111] According to the electronic control device 90 of the hybrid
vehicle 10 of this example, when the rigidity value K is larger
than the preset initial setting value Ki, the output torque
correction control portion 96 decreases the output torque Te of the
engine 12 with the rotation speed Ne of the engine 12 kept
constant, and when the rigidity value K is smaller than the preset
initial setting value Ki, the output torque correction control
portion 96 increases the output torque Te of the engine 12 with the
rotation speed Ne of the engine 12 kept constant. As a result, even
if the rigidity value K of the damper device 26 changes, the
occurrence of the rattling noise and tooth-hitting noise is
suppressed, and preferable fuel consumption of the vehicle 10 is
achieved.
[0112] According to the electronic control device 90 of the hybrid
vehicle 10 of this example, when the hysteresis value H is larger
than the preset initial setting value Hi, the output torque
correction control portion 96 reduces the initial explosion
correction torque Tc output from the first electric motor MG1 for
starting the engine 12 during electric-motor running of the vehicle
10, and when the hysteresis value H is smaller than the preset
initial setting value Hi, the output torque correction control
portion 96 increases the initial explosion correction torque Tc
output from the first electric motor MG1 for starting the engine 12
during the electric-motor running. As a result, even if the
hysteresis value H of the damper device 26 changes, an appropriate
engine start torque is obtained, so that the initial explosion of
the engine 12 is properly performed without an engine start
shock.
[0113] According to the electronic control device 90 of the hybrid
vehicle 10 of this example, when the backlash value G is larger
than the preset initial setting value Gi, the output torque
correction control portion 96 makes the torque increase rate of the
torque output from the first electric motor MG1 larger, so that the
backlash of the damper device 26 is eliminated smoothly and
cranking of the engine 12 is performed as quickly as possible at
the time of start of the engine 12, and when the backlash value G
is smaller than the preset initial setting value Gi, the output
torque correction control portion 96 makes the torque increase rate
of the torque output from the first electric motor MG1 smaller, so
that the backlash of the damper device 26 is eliminated before
starting the engine 12. As a result, even if the backlash value G
of the damper device 26 changes, the engine 12 is started after the
backlash is eliminated smoothly and as quickly as possible, so that
the engine 12 can smoothly be started.
[0114] Although the example of the present invention has been
described in detail with reference to the drawings, this is merely
an embodiment and the present invention can be implemented in
variously modified and improved forms based on the knowledge of
those skilled in the art.
REFERENCE SIGNS LIST
[0115] 10: hybrid vehicle
[0116] 12: engine
[0117] 24: crankshaft
[0118] 26: damper device
[0119] 26a: input-side rotating element (engine-side rotating
element)
[0120] 36: meshing brake (engine-side rotating element fixing
device)
[0121] 90: electronic control device (control device)
[0122] 92: damper rotational characteristic detecting portion
[0123] 96: output torque correction control portion
[0124] G: backlash value
[0125] Gi: initial setting value
[0126] H: hysteresis value
[0127] Hi: initial setting value
[0128] K: rigidity value
[0129] Ki: initial setting value
[0130] MG1: first electric motor (electric motor)
[0131] Tc: initial explosion correction torque
[0132] Te: output torque of the engine
[0133] Tm1: output torque of the electric motor
[0134] Tk: cranking torque
[0135] Tin: input torque
[0136] .PHI.: twist angle
* * * * *